1. Field of the Invention
The present invention relates to a stopper for sealing analysis test tubes, which offers greater guarantees for the operator not to come into contact with the contents of the test tube, especially with blood.
2. Prior Art and Other Considerations
It is known that anybody who operates nowadays in the field of clinical and medical analyses must carefully avoid all contact with the blood to be analysed so as to avert any possible infection.
According to a first widely used technique, blood is taken from a patient by means of a disposable syringe and is then inserted into a test tube provided with a pierceable stopper. The test tube, containing the desired quantity of blood, may be sent to the analysis laboratory as it is, already stoppered but this presents some drawbacks which will be indicated later.
It is also known that for the taking of blood, instead of disposable syringes, the use is becoming increasingly widespread of test tubes inside which a predetermined vacuum has been created to withdraw the required quantity of blood, generally 2.5, 5 or 10 ml. Said test tubes are of glass and are closed by means of a sealing rubber stopper.
When blood is taken from the patient, the use is provided for a device known as a holder, generally made of rigid and transparent plastic material, of a substantially cylindrical shape, having one extremity open and communicating with the outside while the other extremity is closed by a bottom wall provided with an axial seat, generally threaded, for a twin-pointed disposable needle. The point of the needle facing the outside is introduced into the patient's vein while the point of the needle housed in the above holder is, by perforating the rubber stopper, introduced into the test tube under vacuum. The desired quantity of blood is thus recalled into the test tube.
Once the operation is over, the twin-pointed needle is removed from the seat provided and thrown away; the above holder may be used for another withdrawal and the test tube containing the desired quantity of blood may be sent to the laboratory as it is, already stoppered.
Whether the blood has been introduced into the test tube with the first or with the second technique, as often as not the stopper must be removed in the laboratory to withdraw from the test tube the blood to be analysed and during this stage, due to any drops of blood deposited on the lower part of the stopper, the operator runs the risk of coming into contact with blood during said removal.
The need is therefore still keenly felt for a stopper which can adequately protect the operator from accidental contact with blood from patients not only during the stage where blood is taken and handled but also during the stage where it is withdrawn from the test tube to carry out the analysis.